I think betting on Mario Barrios is more reliable.
Watching some of Manny's training videos actually convinced me that he won’t go down that easily. He's old, but he's clearly on a mission to prove that age is just a number. In fact, he even gave a guarantee to fans who are worried about his comeback, saying that he knows his own body and understands exactly what he's doing.
So , just for fun, I think I’ll take a shot and bet on Pacman to win ..either by decision or KO.
Two different outcomes, two bets. Why not?

Manny is good in his training; he has always been that way, but in training, you do not exhaust your body and inflict damage on it, unlike in real fights.
I have doubts about betting on Manny; he will be good in the first four rounds, but after that, he will be absorbing power punches from his young opponent, and that will have an impact on his old body.
His last fight against a Japanese looked bad; he was being beaten at will. How does that Japanese compare to Barrios, who is a champion and at the height of his power? I think Barrios is going to be the one to retire Pacquiao for good. Finally, I hope he will not be hurt.